Method and system for high pressure liquid injection of turf seed

ABSTRACT

A turf care system and method uses simultaneously fired pulses of high-pressure liquid jets of the mixture shot toward the ground. The liquid is mixed with dry grass seed shortly before being delivered to a high-pressure liquid/seed pumping system, which uses an accumulator and sequencing valve to produce at regular repetitive intervals pulses of the liquid/seed mixture under high pressure. The pulses are delivered to an elongated hydraulic manifold having multiple nozzles pointed downwardly, which are spaced from one another and the ground by predetermined distances. The momentum of the high-pressure jet of liquid/seed mixture issuing from each nozzle cuts through overlying vegetation to deposit the seeds into the crown of the soil at predetermined desired depth. Spray patterns are determined by nozzle orifice shape, and are preferably selected to provide a shallow knife slit-like opening or trench in the crown of the turf.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of presently U.S. patent applicationSer. No. 09/679,319 filed on Oct. 4, 2000, now U.S. Pat. No. 6,431,096the disclosure of which is incorporated by reference and which is basedon U.S. Provisional Application Serial No. 60/157,557 filed Oct. 4,1999.

FIELD OF THE INVENTION

The present invention generally relates to turf care methods and systemsfor injecting seeds into the turf or soil using pressurized liquid, andin particular to methods and systems for taking a liquid-seed mixture,pressurizing it, and injecting it under pressure into the crown area ofan established stand of turf.

BACKGROUND OF THE INVENTION

The release of several new grass cultivars with higher shoot density,finer texture, and greater tolerance to environmental stresses has ledmany golf course superintendents to think about how best to introducethese new cultivars into their greens, tee-boxes and fairways. There aretwo primary methods of introducing a new grass species into anestablished turf grass stand: total renovation and interseeding. It istraditionally thought that the most effective means to replace an oldgrass cultivar with a new one is through total renovation. This consistsof killing or removing the established turf grass and thenreestablishing the area with a new cultivar. The downside to thisapproach is the requirement to close the greens or fairway until the newturf is established. The reestablishing process normally takes at leasta few weeks and could last as long as several months, during which timesignificant loss of play and hence revenue would occur.

An alternative method to total renovation of greens is a practice thatis known as interseeding. In interseeding, the new, desired cultivar isintroduced into an established stand of grass over a period of time. Thedesired result is a gradual conversion of the existing putting green,tee-box or fairway surface from that of an older cultivar to onecontaining the desired cultivar without as serious a disruption to theplaying surface.

Traditionally, the practices used in interseeding are similar to oradapted from practices used to overseed bermuda grass greens with acool-season turf grass during the autumn. Generally, interseedingpractices consist of trying to provide the best seed-to-soil contactpossible without totally destroying the established turf surface.Verticutting, aerification with multiple small incisions, solid and/orhollow tine coring, and top dressing are used in various combinations ininterseeding programs. The intensity of most of these practices isgenerally not severe enough to significantly disrupt or limit play.Practices that attempt to limit the competitiveness of the establishedturf, such as using plant growth regulators or mowing at a shorterheight of cut, may also be used.

Traditionally, following the mechanical preparation, the desiredcultivar is broadcast or slit-seeded into the stand. The seeding rate,in many cases, is higher than the normally recommended rates forestablishment. Within a few weeks of seeding, small seedlings areobserved.

Unfortunately, the germinating seeds often have a difficult timecompeting with the existing grass population for light, water andnutrients. Currently, it is thought that in order for interseeding to besuccessful, the established turf grass stand would have to be severelystressed and/or a significant amount of the turf grass canopy removed.Practices such as a severe scalping of the turf may be used to reducethe competitiveness of the established turf, which often is a bentgrass, to a level that the desired cultivar would have a chance.Practices that destroy the turf canopy and create open spaces generallyhelp reduce competition from the existing bent grass plants to allow thenew seedlings to have a better chance of successful development. Giventhe significant and the continuing amount of work that has to be done ina given area to interseed successfully, many believe that theintroduction of a new cultivar is best or most expeditiouslyaccomplished through total renovation.

In the science of turf care, many methods have been suggested whichimprove germination rates as well as improve survivability ofestablished turf grasses. Many of these methods relate to bringingadditional nutrients to the root zone of the grass to efficiently aid inthe growth of the turf. It has long been understood that liquids can beinjected into soils to reach the root zone. The injection of liquidsprovides a mechanism to introduce water, nutrients, fungicides, and/orpesticides into the ground and further provides a means for aeration ofthe soil, which also aids turf growth. A number of exemplary U.S.patents describe and illustrate such processes and equipment.

U.S. Pat. No. 4,009,666 to Russell et al. discloses an apparatus forinjecting fluid below a soil or turf surface. The apparatus is comprisedof a plurality of nozzles carried by a support rod; each nozzle forms astream of fluid passing therethrough has a low friction contact surfacefor contacting the surface of the soil. The apparatus is provided with apump that cooperates with the nozzle to inject fluid substantially belowthe soil surface.

U.S. Pat. No. 4,807,544 to Cross et al. discloses an apparatus forinjecting agro-chemicals into the subsurface of the soil without tillingthe soil. The high pressure pump delivers the solution to be injectedinto a series of injection nozzles that cause liquid jets to be formedthat have sufficient velocity and narrow cross-section to inject intothe soil. Included in the design is a shield-pan that minimizes cloggingof the nozzles.

U.S. Pat. No. 5,407,134 to Thompson et al. discloses a liquiddistribution system having a pair of variable displacement pumps formixing chemicals and water to a desired proportion and delivering thesolution to an open furrow just prior to the furrow being covered withsoil.

U.S. Pat. No. 5,487,346 to Taylor discloses an apparatus forintermittently injecting liquid into soil at pressures as high as 1200PSI and at desired flow rates of between 6 and 60 gallons per minute. Anaccumulator and sequencing valve is used to control the amount of fluidsbeing injected into the ground. (Note that the apparatus shown in thispatent is also shown in FIG. 1 herein.)

U.S. Pat. No. 5,503,091 to Foster et al. discloses a turf conditioningmachine which disperses a high pressure stream of fluid into the groundin a vertically-aligned cylindrically-shaped drilling hole. The holesare drilled using a hydrated polymer that has absorbed and thus willrelease moisture in a controlled fashion.

U.S. Pat. No. 5,741,090 to Dunning et al. discloses a system and methodfor injecting liquids and solids into the earth. The system discloses asetup wherein only the liquid is run through the main pump while aliquid solid slurry is stored and moved to join the liquid underpressure by a chemical injector pump. A displacement wheel commandssolenoid valves for pulsing the pressurized liquid into the groundsurface.

Several U.S. patents disclose methods for injecting seeds or particulatematter mixed with a fluid into the ground typically through the use of apressurized steam of liquid. Exemplary patents include the following.

U.S. Pat. No. 4,145,980 to Boots discloses an automatic seeder forplanting tiny seeds at a given depth and at evenly spaced intervals. Theapparatus utilizes a plurality of furrow creating mechanisms that arearranged to create furrows of a consistent desired depth in front of theseed discharging means. A spray arrangement is used to cover thedisbursed seeds with water.

U.S. Pat. No. 4,218,855 to Wemmer discloses a particulate spray nozzlehaving an internal mixing-chamber with a liquid spray orifice. When aliquid is sprayed through the liquid supply orifice, particulate matteris drawn into the mixing chamber by a venturi facilitating the mixing ofthe dry material with the liquid. This material is ejected through aport on one side of the mixing chamber.

U.S. Pat. No. 4,224,889 to Cruse discloses an apparatus for sowing seedsin a liquid suspension. The liquid seed combination is discharged behindthe plowshare into a furrow.

It is also known and has been shown to inject single seeds into turf orground. U.S. Pat. No. 4,899,672 to Paul discloses a method for sowingseparate seeds in a furrow made by a plowshare. The device, which trailsthe plowshare, traps a single seed and injects it through a nozzle intoa furrow before the furrow is closed.

U.S. Pat. No. 5,303,663 to Salstrom discloses a method and apparatus fordischarging water absorbent polymers into a “blanket” near the root zoneof a crop plant.

U.S. Pat. No. 5,394,812 to Dunning et al. discloses an apparatus andmethod for dispensing a substance such as a hydrophylic polymer into asoil to minimize the need for repeated irrigation. The apparatus iscontained on a trailer that supports a mixing tank within which thepolymer and liquid are continuously agitated. The mixture, in a liquidform is sent through a pump to an outlet having a plurality of aperturescommunicating with the tank via a manifold. A series of valves operatessuch that high pressure pulses of the liquid polymer mixture aredischarged with sufficient velocity that the slugs of material aredischarged under the soil. There are still other fluid and fluidparticulate injection systems, beyond those disclosed above, thatutilize a venturi to mix particulate materials with fluids and injectthem into the ground.

Common among all of these, to our knowledge is a lack of a system withthe capability of simultaneously planting seeds by high-pressure liquidinjection over a dispersed area. Further, to our knowledge, no one hasused a high-pressure liquid injection system for planting seeds into anestablished stand of turf.

Accordingly, there is still a need for more efficient methods andsystems for planting seeds into the crown area of an established standof turf for interseeding purposes. In particular, there is a continuingneed for easy-to-use, inexpensive-to-operate and non-complicated methodsand systems for safely and easily accomplishing seeding of existinggrass areas with less disruption to the playing surfaces to be seeded.Preferably such new methods and systems should produce near optimalresults in terms of achieving desired depth of seed placement into thesoil and achieving successful seed germination rates and seedlinggrowth. Also, on a more general level, there is a continuing need tofind improved methods and systems for planting seeds over large areaswith less effort, reduced expenditure of energy, and reduced minimaldisruption to the existing turf, vegetation or soil to be planted.

Thus, objects of the present invention include providing:

(1) a liquid/seed injection (“LSI”) system and method for simultaneouslyinjecting multiple seeds into the turf or ground to a desired plantingdepth over a distributed area using high-pressure (“HP”);

(2) a high-pressure liquid seed injection (“HP-LSI”) system and methodwhich, by the way it works, helps protects the seeds from physicaldamage during and after planting;

(3) an HP-LSI planting system and method which can be used to interseed,that is, plant within an existing well-established turf population;

(4) an HP-LSI planting system and method which permits a gradual, timed,introduction of new seeds into existing stands with minimal surfacedisruption;

(5) an HP-LSI planting system and method which allows for the plantingof seeds without mechanical tillage of the soil and/or soil cover;

(6) an LSI planting system and method where the mixing of the dry seedsand the liquid can be easily and quickly accomplished in one locationshortly before injection;

(7) an LSI planting system and method which subjects the coat of theseeds to be planted to an agronomically acceptable and desirable amountof scarification; and

(8) an LSI planting system and method which reduces the amount of energyand water needed to plant seeds;

(9) an LSI planting system and method which enables a large batch ofseeds to be efficiently and automatically planted at a desired depthinto soil over a large area, with the multiple seeds being plantedsimultaneously in a predetermined pattern and with the pattern beingrepeated and spaced at predetermined intervals from one another; and

(10) a new application for the basic high-pressure liquid pumping andinjection systems now being used for high-pressure injection ofliquid-soluble fertilizers, pesticides and the like, but not heretoforemodified and arranged to plant seeds, thus helping make such injectionequipment more versatile.

SUMMARY OF THE INVENTION

To address the foregoing needs and achieve one or more of the foregoingobjectives, there is provided, according to a first aspect of thepresent invention, a high-pressure liquid seed/injection system forsimultaneously injecting multiple jets of a liquid/seed mixture into theground, such as the crown of an established stand of turf, or barren orcultivated soil. The jets of liquid/seed mixture are preferably sprayedout of nozzles that each have an opening which provides a predeterminedsprayed pattern, such as a dashed straight line, circle, cross or oval.

The present invention provides a seed-planting system includingmachinery having an accumulator for storing a seed-fluid mixture underpressure coupled to a nozzle. The machine further contains a pump forincreasing the pressure of the seed-fluid mixture and a mechanism forregulating the flow of the seed-fluid mixture from the accumulator tothe nozzle. In accordance with a first aspect of the present invention,a seed injection system is provided for injecting seed into barren soilor for interseeding into existing crops. The seed-fluid injectingmachine preferably comprises: a nozzle, which has a fan or conicaldistribution pattern; and an accumulator for storing the seed mixtureunder pressure coupled to a nozzle. A plurality of nozzles are evenlydistributed along a manifold which accepts the pressurized fluid fromthe accumulator. The manifold and nozzles are suspended above the groundat a distance which allows for the maximum distribution of theseed-fluid mixture while preventing the injection jets from overlappingsize and its orifice pattern.

The distribution pattern of the jets is tailored to cause a properspatial and depth distribution of the seeds in the turf crown or soil tobe seeded. This distribution of the liquid/seed mixture is a function ofnozzle size, spray pattern, accumulator size, system pressure settingsand soil conditions. For use in an interseeding operation, the nozzlespreferably have a fan or cone-shaped spatial distribution pattern. Onepreferred form and arrangement of the fan-spray nozzles allows for adistribution or injection pattern of the seed-liquid mixture along astraight line in the form of dashes. These dashed lines are preferablyspaced at even intervals along the surface of the area to be reseeded.In interseeding applications, other spray pattern configurations areusable. It is preferable that the spray patterns do not overlap beforethey hit the ground.

The LSI machine or system is mounted on the back of a small off-roadutility truck with large tires such as a Cushman Turf-Truckster(“Vehicle”), which features a powered takeoff (“PTO”) shaft which isavailable to drive the mixing paddles and the drive shaft of the pistonpump found in the unit. This LSI machine or system, which at times isreferred to as a unit, is preferably set up to fire at pressures up to3600 PSI. In other words, the sequencer valve opens at that pressure. Ifthe pressure is increased (by adding additional Belleville springs tothe sequencer valve), the energy of the liquid as it leaves the nozzleis increased, thus driving the liquid deeper into the soil. A preferredfan spray nozzle produces a spray pattern that covers an area of about3.5 inches to 4 inches when the nozzles are placed 6 inches above thetop level of the soil, and sprayed out in a line.

The preferred unit contains a 6 cubic inch accumulator. There are 6-8pulses per second typically produced with the 6 cubic inch accumulator.If a larger accumulator is used, such as the 20 cubic inch accumulator,the number of pulses per second is reduced, and more energy and liquidunder pressure is stored between shots. The net result, is that eachburst of liquid will inject more fluid and inject it more deeply intothe soil than is desirable for planting grass seeds.

It is preferable to have 16 nozzles on the manifold, the nozzles beingabout 4½ inches apart. The fan nozzles spray in a spatial distributionfor interseeding purposes in what amounts to a straight line. Afterinjection, the treatment looks like the dashes in Morse Code. A typicalspeed for the small utility truck is 1½ to 2 miles per hour. At thisspeed, the lines of pulses with a 6 inch accumulator are about 2 inchesto 2½ inches apart. This spacing is acceptable because the grass seedinjected in the top layer of soil in these parallel line rows will growtoward one another, thus providing the desired coverage.

A typical golf course green is about 7,000 square feet, and can bespray-planted in a single session with about 160 gallons of waterprovided in the 160 gallon tank on the unit. This spraying operationtakes 25 minutes on average, and typically will cover the entire greenby traversing the green with the utility truck-mounted turf seedinjection system in two orthogonal directions.

The use of a fan spray nozzle allows for a small shallow elongatedopening about 4 inches long and ⅛ inch to ¼ inch wide to be created. Aswill be further explained, the LSI system and method of presentinvention use the high-pressure bursts or jets of liquid and seedmixtures to cut through existing vegetation and dig this shallow“seed-starter” trench. The maximum depth to which the creeping bentgrass, a typical grass seed used on golf courses, should be planted isabout ¼ inch. The planting of seeds at depths of greater than ¼ inchsignificantly reduces the seedling's ability to emerge from the soilsurface. Accordingly, the various parameters of the LSI system of thepresent invention are set or adjusted until the depth of injection intothe soil reaches the desired depth. The fan spray nozzle preferably usedis a Spraying Systems nozzle tip part No. ¼ MEG-65054. It is during theformation of this seed-starter trench that the seeds are also injectedat high pressure, thus becoming lodged in the crown area of theestablished turf or top layer of the soil. This high-pressure spray hasthe beneficial effect of cutting and/or partially clearing away theexisting grass blades and root structures, which otherwise might competeagainst the new grass seedlings. This partial cutting provides ashort-lived stunting action to the existing turf stand, which helpsinhibit the growth of immediately adjacent existing plants, thusallowing the newly germinating seeds to compete more effectively forlight, nutrients and air.

The disruptive effect of producing these shallow trenches in theexisting turf fortunately does not seriously disrupt the turf'sinterwoven turf substructure, so that players and vehicles can stillpass over the soil without significant displacement of the turf in onedirection or another. The seed is effectively placed in excellentsoil/thatch contact where it is provided with moisture and physical soilcontact. It is also protected from physical damage by adjacent turfsubstructure still present on either side of the trench. The adjacentcanopy holds moisture and physically protects the newly created seed bedfrom drying winds and desiccant, thus requiring less frequent irrigationduring the germination process. One of the benefits of the seed-plantingmethods of the present invention is this very shallow depth of cut,which is made only as deep as it needs to be to achieve the desiredbeneficial results to stimulate rapid germination. The providing of atrench into which water will flow and into which water, nutrients andsoil can collect and into which light can enter creates an idealenvironment to stimulate and support germinating seed. Heretofore, therewas no known way, except the use of mechanical cutting tools likeverti-cuts or elongated mechanical tines to achieve selective trenchingfor overseeding. In addition, there was no practical way of accuratelycontrolling the depth of the trenches or slits produced by thoseconventional methods. In the present invention, this depth-controloccurs automatically through the selection of the proper height of thenozzle above the soil and the spray pattern in combination with thepressure and volume, so as to cut the grass and/upper soil regions tothe proper depth.

In denser soil, it is important not to place the grass seed too deep;whereas in less dense soil, a seed placed slightly deeper still has adecent chance of reaching the surface. The pressurized liquid/seedmixture issuing from the nozzles of the liquid-seed injection systeminherently penetrates more shallowly into dense soil than into loam orless dense soil. This is because the denser soil more quickly absorbsthe kinetic energy or momentum of the jet stream (which is a function ofthe volume and speed of water injected into the soil). Thus, the presentinvention provides a self-correcting system and method for placing theseeds at the proper depth, depending upon soil, turf canopy and rootstructure density.

One of the beneficial effects of the natural dormancy of seeds is thatthey are normally dry, and therefore typically very hard. It is thepresence of water which causes the seed coats to soften in a processknown as imbibing or imbibition. In the present grass seed injectionprocess, it is beneficial to put the load of seed to be planted in themixing tank just before it is to be injected so that it does not haveany significant opportunity to imbibe much water and thus become so softthat it would be more susceptible to damage as it travels through thesystem and is injected into the turf crown or soil. Preferably, creepingbent grass seeds remain in the holding tank no more than twenty minutesbefore being injected into the ground.

One beneficial effect of the seeds passing through the high pressurepump, manifold, hydraulic lines, fittings, sprayer bar header andnozzles and through the top soil, is that the seed is typicallymechanically scarified, meaning that its seed coat is nicked up, orpartially cracked or fractured. This agronomically acceptable amount ofscarification makes it easier for the seed embryo to imbibe water andnutrients and to germinate through the seed coat, which is an essentialfactor in the successful part of the embryo growth cycle.

Although the testing to date has been with interseeding over an existingpopulation of established grass having a grass canopy and rootstructure, the methods and machinery of the present invention can bebeneficially used for original seeding as well. Both the fan spraynozzles and the cone nozzles may be used for this purpose. The conenozzles may work better to the extent that they provide for a moreuniform spatial distribution of the grass seeds over an area.

The machinery is particularly well suited for the original seedingprocess because it comes with an onboard mixing tank. In this way, theseed, fertilizer and any other desired water-soluble constituent such aswater-absorbing polymers, can all be placed into the water and keptunder agitation to help ensure substantially uniform distribution withthe tank.

In testing of the method and machine of the present invention, seed ofknown quality was used. In other words, the seed batch was pre-tested toensure that 95% or more of the seeds in the batch were alive at the timethe seeds were used. Testing with the fan spray nozzles, 6 inchaccumulator and the unit mounted on a utility vehicle show that there isapproximately a 25%-27% mortality rate for the creeping bent grassseeds. In other words, 73%-75% of the seeds survived and successfullygerminated. Considering seeding rates of 8-16 million bent grass seedsper 1000 square feet, this survival rate is highly acceptable.

The ability of a seed, like a grass seed, to pass through this veryhostile mechanical environment where the rate of travel and the impactsare very high and the deceleration is extremely severe (on the order ofmany g's) is counterintuitive. Yet because the seeds have a dry centerrather than a fluid center, there appears to be little or no opportunityfor detrimental movement between the embryo and the inner seed coatwall.

Further areas of applicability of the present invention will becomeapparent from the detailed description provided hereinafter. It shouldbe understood that the detailed description and specific examples, whileindicating the preferred embodiment of the invention, are intended forpurposes of illustration only and are not intended to limit the scope ofthe invention.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings, various embodiments and aspects of the liquid-seedinjection system and methods of the present invention are shown. Forpurposes of illustrating the features and advantages of the presentinvention, the Figures, in the interest of clarity, at times exaggeratesomewhat the size, spacing, clearances and/or relative size of orbetween certain parts of the seed injecting device. In the variousFigures, like numerals indicate similar components or features and thefigures may be briefly described as follows.

FIG. 1 shows a liquid injection system as is known in the prior art.

FIG. 2 shows a view of the seed-liquid injection system mounted on aconventional small off-road utility truck.

FIG. 3 shows an exploded view of the liquid distribution system of thepresent invention.

FIGS. 4-6 show first, second and third embodiments, respectively, of thespray nozzle configuration and distribution patterns of the presentinvention, wherein:

FIG. 4 is a perspective view of the first embodiment which includes anumber of nozzles distributing the liquid-seed mixture in a parallel fandistribution configuration.

FIG. 5 is a perspective view of the manifold and nozzles showing thenozzles injecting the seed-fluid mixture using a perpendicular fanconfiguration.

FIG. 6 is a perspective view of the third embodiment which shows thedistribution of the fluid-seed mixture using a number of parallel conespray distributions.

FIG. 7 shows a close-up view of a nozzle discharging the liquid-seedmixture into the ground; and

FIG. 8 shows a cross-section of the seed-fluid mixture injected intoturf environment.

FIGS. 9-12 show alternate spray pattern configurations.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The following detailed description of various embodiments of theseed-fluid injection system of the present invention are presented in away of example only and are not intended to limit the invention to justthose embodiments and methods shown and/or described. This turf seedinjection system is intended primarily for use in the turf careindustry, but may be used in other agricultural arts such as for theplanting of cash crops. The seed-fluid injection device may be viewed asa larger version for injecting larger seeds such as corn or soybeans.These larger devices would of course be adapted by the use of largeraccumulators and/or nozzle heads to accommodate the larger seeds andplanting depths. Thus, the overall scope of my invention here should beunderstood to encompass the adaptations, variations, alternatives anddifferent uses of the device that are described herein or are logicallyderived from the teachings herein. The fluid-seed injecting devicedisclosed herein has structures dedicated towards a single manifold witha number of nozzles attached thereon. It should be understood that aplurality of accumulators coupled to the nozzles as well as thepossibility of a number of individual manifolds is envisioned. Those inthe art should appreciate that the descriptions herein of the liquiddistribution system will also serve to describe proportionally largerunits for use with seed planted cash crops.

The prior art system as shown in FIG. 1 of U.S. Pat. No. 5,487,346 toTaylor, has a holding tank 12 (preferably a vented tank to inhibitover-pressurization) for holding water and/or water with pesticides,fertilizers or similar material to be injected into soil. Water issupplied to tank 12 from a water supply source 14 through flow line 16.Preferably the water is passed through a fairly fine filter 18 to removeany debris that might be present in the water so as to help avoidobstructing the relatively small orifices in the lines and nozzlesdownstream. The above-mentioned materials to be added to the tank areadded either to fluid supply source 14, into flow line 16 at point 22,or into tank 12 through inlet 24. Valve 20 controls flow in line 16.

Air under pressure is supplied into the tank from manifold 26 withmultiple air outlet holes through flow line 28 from air compressor 30.Gauge 32 indicates air pressure in flow line 28. This pressurized airhelps to mix fluid and materials in tank 12, and may be supplied atabout 120 p.s.i. (Note all pressure valves used set forth herein areexpressed as p.s.i.g.)

Transfer pump 40 pumps fluid through flow line 34 to flow line 36 forintroduction to triplex pump 50. In a tractor-mounted (or truck-mounted)system according to the present invention, items forward from andincluding connection 42 are mounted on the tractor (or truck) (notshown). Hose 44 interconnects two flow lines 34 and 36 at connections 42and 46.

Flow lines 34 and 36 may be relieved by through line 48 by relief valve83. Valve 83 provides relief of flow line 34 via an interconnection withit through flow line 52 and to flow line 36 via interconnection withflow line 44 (e.g., a hose). In one embodiment, relief valve 83 is setto open at a line pressure of between about 83 and 75 p.s.i. (e.g., whenthe inlet of the pump 50 has a maximum inlet rating of 80 p.s.i.).

Gauge 54 indicates fluid pressure in flow line 36. Inlet drain valve 56provides for draining and testing the system.

Triplex pump 50 pumps fluid at a relatively high pressure through flowline 58 to accumulator 60. Relief/dump valve 62 provides relief to flowlines 76 and 58 via flow lines 64 and 66. Valve 62 acts as a reliefvalve for over-pressurization protection and as an automatic dump valvewhen valve 86 on the tractor unit is placed in an OFF position. Valve 62will remain in an open (dump) position until valve 86 is placed in an ONposition for injection. Gauge 68 indicates line pressure in flow line58. For added safety, high pressure rupture disc assembly 72, e.g., witha disc that ruptures at a pressure of e.g. about 6500 p.s.i., isinterconnected with the outlet side of triplex pump 50 to provide quickpressure relief in the event of a failure of valve 62. (The disc may beconstructed to rupture at some pressure reasonably above the normalexpected operating pressures.) Valve 74 in fluid communication with flowline 58 via flow line 76 provides for bleeding of fluid for pump 50,relieving pressure on the pump discharge. The motor on pump 50 will notstart under a load.

A charge of a volume of fluid under pressure, pumped by triplex pump 50into accumulator 60, builds up in accumulator 60 and in flow line 78until sequence control valve 80 with diaphragm 81 senses, via sensingline 82, that a pre-set line pressure has been reached. At this pointvalve 80 opens allowing the accumulated fluid charge to flow through aflow line 84 to a tractor-mounted nozzle apparatus 90. The accumulatorcontains an amount of a gas, e.g., nitrogen gas 96. An on/off adjustablecontrol valve 86 operable from a tractor, controls flow in line 84.Nozzle apparatus 90 has a plurality of nozzles 88.

Gauge 92, e.g., mounted on the tractor, indicates the level of linepressure in flow line 78. Manually-operable drain and balancing valve 94permits draining and testing of the system.

FIG. 2 illustrates a general arrangement of the utility vehicle havingthe turf care machinery and system of the present invention attached.Utility vehicle 100 includes frame and 112 supported for movement onrear drive wheels 114 and steerable front wheels 116. Injection assembly118 is shown fixed to the back of utility vehicle 100. Manifold assembly90 (not shown) is within injection assembly 118 and held 6 inches (about15 cm) above the turf. Manifold assembly 90 is fluidly coupled to theinjection pump 50 by high pressure hose 84.

Utility vehicle 100 carries a 160 gallon storage tank 112 and a pump setto discharge 8 gallons per minute. The 8 gallons per minute is a flowrate associated with the pump engine being set to run at a certain RPM.The pump is run by a separate gas motor; turn it on and off by a key;run off same gas tank; flip the lever to start and stop pulsating; PTOruns agitation inside the tank, pretty good agitation; seed floats ontop; water is recirculated back to tank. When run at this speed, theunit produces pulses 2-3 inches apart.

Mechanical agitator 13 is provided in storage tank 12 that allows theseeds to be maintained in a suspension in a substantially density (i.e.,number of seeds/unit volume) in the liquid. In general, a uniformdistribution of the seeds in the tank is desirable, although the tankwhich has less liquid typically contains a higher concentration ofseeds. The seeding operation is carried out by moving continuouslyacross the seeding area since if one stops, there would be multiplepulses delivered in the same location, if the injection is not turnedoff first. It is envisioned that it is possible to correlate the firingof the pulses to rotation of the utility vehicles wheels to prevent thisproblem. Typically, shutoff mechanisms can be provided for the pump 50to stop its pumping when the pressure in the accumulator 60 is reachedbut the sensors determine it is not desirable to discharge theliquid-seed mixture. This can be accomplished for example by simplyturning off the PTO, which is engaged and disengaged by a clutch.

FIG. 3 shows a first embodiment of the seed-fluid mixture injectionsystem of the present invention, which is scaled in size in order toserve as a turf seed injection system. The device includes storage tank12 having agitator 13 for agitating the fluid and seed mixture. Agitator13 can take any suitable form including a mechanically-driven rotatingpaddle or fluid jet system. As can be appreciated, fluid can be passedto storage tank 12 through input line 16 or through the tank cover 17.Dry materials such as seeds, as well as dry fertilizer that is to berapidly dissolved within tank 12, can be placed within the tank'sopening 17. Pump 50 may be a positive displacement high pressure pumpwith a delivery or output of 8 g.p.m. at 3,500 p.s.i. Pump 50 is used totransfer the fluid from tank 12 to the accumulator 60. A charge of thehigh pressure liquid builds up in the accumulator 60 until apredetermined pressure has been reached. At this point, the valve 80opens allowing the accumulator fluid to flow through the flow lines tothe manifold apparatus 90 and through the nozzles 188. It must be noted,that the nozzles 188 are of a fan, cross or cone configuration. Further,these nozzles are displaced from about 4 inches to about 8 inches andpreferably 6 inches above the ground. FIGS. 4, 5 and 6 show envisioneddistribution patterns of the high pressure ejected fluids 122. Themanifold 90 and corresponding nozzles 188 are shown 6 inches (about 15cm) above the ground. This particular arrangement in combination with a6 cubic inch accumulator allows for the proper pressure and fluid volumeto allow for grass seeds to be distributed at a depth of ¼ inch (about 6mm) in the turf.

FIG. 4 shows a fan nozzle configuration discharging to form a dashedline spray pattern. As can be seen, the spray pattern is repeated atfrom 1 to 3 and preferably 2 inch (5 cm) intervals to allow for theproper propagation of the new seeds. This distance may be modifiedespecially if different species are being planted.

FIG. 5 shows manifold 90 and nozzle assembly 188 having nozzlesconfigured to distribute the high pressure grass seed-fluid mixture 122in a cross-hatch pattern. It is envisioned that the use of a cross-hatchpattern in combination with a larger accumulator, 12 cubic inches or 20cubic inches, will allow for a single sweep seeding of an area asopposed to using multiple passes.

FIG. 6 shows the use of a conical distribution pattern for thedistribution of seeds within the turf grass. As with the cross-hatchpattern, it is envisioned that the conical distribution pattern willallow for a single pass to reseed an area. Note that we envision thatstill other distribution patterns may be used to inject the seed-fluidmixture into the ground, such as but not limited to oval patterns, starpatterns and hexagonal patterns.

FIG. 7 shows a side view of a nozzle injecting the fluid-seed mixtureinto turf grass. As can be seen, the nozzle is about 6 inches above theground. Further, the stream of the liquid-seed mixture passes or cutsthrough the grass and thatch to a depth of about ¼ inch into the soil.As shown, the existing root structure of the grass material, which ismostly below this depth of injection, is not significantly adverselyaffected by the injection of these seeds. This allows for the continuedlife of these elongated thick grasses although they may be stunted dueto the injection process. Further shown are bank of brushes 120. Thesebrushes sweep any debris generated by the injection process deeper downinto the existing turf. The row(s) of brushes also help guard againstaccidental encounters by persons with the high pressure jets 122. Inother words, the brushes 122 form a physical barrier that makes it muchmore difficult to accidentally place any part of the body, such as one'sfoot, hand or even fingers, directly under the high pressure jet streamof liquid emanating in periodic bursts from the nozzles.

FIG. 8 represents a sectional view of the seed-fluid mixture after beinginjected into the ground using a fan type nozzle. As can be seen, theseeds are placed at an appropriate depth with respect to the soilsurface and thatch material. Furthermore, optional dissolved polymermaterials may also be delivered with as part of the liquid injectionjet. In this manner, the hydrated polymer materials are in a closevicinity to the seeds to help assure that proper water/moisture levelsare maintained early in the seed's growth cycle for near-optimalgermination.

Those in the art should appreciate that the seed injection system andmethods of the present invention may be used with other vehiclesincluding tractors and other lawn care equipment. Also, the seedinjection systems and methods disclosed herein can be profitably usedfor other planting applications such as the planting of cash crops.

Thus, it is to be understood that the seed injection devices of thepresent invention are by no means limited to the particular constructionand uses herein disclosed and/or shown in the drawings. Instead, thepresent invention also encompasses many modifications or equivalentsthat are fairly covered by the claims set forth below.

What is claimed is:
 1. The mechanism for injecting a liquid-seed mixtureinto soil having: a nozzle; an accumulator for storing the liquid-seedmixture under pressure coupled to the nozzle; a pump for increasing thepressure of the liquid-seed mixture; and a regulator for regulating theflow of the liquid-seed mixture from accumulator through the nozzle,wherein the nozzle is configured to inject the liquid-seed mixture intothe soil.
 2. The mechanism of claim 1 further comprising: a fluidsupply; and a seed supplier for mixing the seed with liquid storedwithin the fluid supply.
 3. The mechanism of claim 2 further containingan agitator for mixing the seed within the liquid.
 4. The mechanism ofclaim 3 wherein the accumulator has a volume from about 5 to about 20cubic inches.
 5. The mechanism of claim 4 wherein the accumulator has avolume from about 6 to about 12 cubic inches.
 6. The mechanism of claim5 wherein the accumulator has a volume of about 6 cubic inches.
 7. Themechanism of claim 3 wherein the nozzle discharges the liquid-seedcombination in a fan pattern.
 8. The mechanism of claim 3 wherein thenozzle is disposed from about 4 to about 6 inches above the ground. 9.The mechanism of claim 3 wherein the liquid is water.
 10. The mechanismof claim 9 wherein the liquid further contains a dissolved fertilizersolution.
 11. The mechanism of claim 9 wherein the liquid furthercontains a dissolved polymer material.
 12. The mechanism of claim 1further comprising a metering mechanism for controlling the amount ofseed-fluid mixture discharged by the nozzle.
 13. A mechanism forinjecting a seed-liquid mixture into a turf grass bearing mediumcomprising: a support frame having at least one rotatable wheel; aninjection nozzle for directing periodic amounts of a seed-liquid mixtureinto the turf grass bearing medium; a liquid supply system coupled tothe support frame, said supply system configured to provide pressurizedliquid to the injection nozzle; a seed supply system for introducingseed into a liquid before the injection nozzle; a metering mechanism forcontrolling the amount of liquid discharged by the nozzle; and acontroller being operatively coupled with the metering mechanism and tothe wheel, said controller configured to control the amount of fluidbeing discharged as a function of rotation of the wheel.
 14. Themechanism of claim 13 wherein the liquid supply system contains anaccumulator for accumulating the pressurized liquid having a volume fromabout 5 to about 20 cubic inches.
 15. The mechanism of claim 13 whereinthe liquid supply system further includes a pump for pressurizing theseed-liquid mixture and transporting the seed-liquid mixture to theaccumulator system.